Spot-type disc brake having a sliding caliper

Abstract

In a spot-type disc brake guides are arranged between each of the arms of a brake support and the sliding caliper to permit displacement of the sliding caliper and the transmission of braking forces to the brake support. The guides each have a guide body comprising a groove extending in the direction of the axis of rotation of the brake disc as well as a projection engaging into said groove. To enable exceptionally high braking forces also to be transmitted by the caliper via the guides to the brake support, the groove and the projection of each guide, which upon braking in the operational direction of rotation of the brake disc is loaded with braking forces, have complementary circularly arcuate profiles in cross-section parallel to the brake disc.

I claim: 
     
       1. A spot-type disc brake comprising a brake support member (10) having on at least one side of a brake disc (12) a pair of arms (14, 16; 18, 20) offset with respect to each other in the direction of rotation (22) of the brake disc (12),   two brake pads (24, 26) adapted to be applied to one side each of the brake disc (12),   a sliding caliper member (28) straddling the brake disc (12) as well as the two brake pads (24, 26),   an actuator (34, 36) arranged at one side of the brake disc (12) on the sliding caliper member (28) to urge one of the brake pads (24) directly against one side of the brake disc (12) and the other (26) pad against the other side of the brake disc by moving the sliding caliper member (28), and   guides (30, 32) which are each arranged between one arm of the support member (14, 18; 16, 20) and the sliding caliper member (28) to allow movement of said caliper member and to transmit braking forces onto the brake support member (10), each guide comprising a guide body (50) having a groove (54) carried by one of said brake support and caliper members and extending in a direction parallel to the axis of rotation of the brake disc (12), and a pin carried by the other of said members and extending in a direction transverse to the disc axis, said pin including a projection (56) at one end engaging into said groove, characterized in that the groove (54) and the projection (56) of each guide (32), which upon braking in the normal direction of rotation (22) of the brake disc (12) is loaded by braking forces, having complementary circularly arcuate profiles when viewed in a plane parallel to the plane of the brake disc (12), each of the projections (56) being formed by a spherical segment at the end of its pin (60).   
     
     
       2. The spot-type disc brake as claimed in claim 1, characterized in that the groove (54) and the projections (56) of all the guides have complementary circularly arcuate profiles. 
     
     
       3. The spot-type disc brake as claimed in claim 2, characterized in that the groove (54) of at least one guide (30) which is relived of braking forces during braking in the normal direction of rotation (22) of the brake disc (12) has approximately parallel wall sections (76) adjacent the semi-circular profile of the groove (54) for guiding the associated projection (56) even when it does not contact the semicircular profile of the respective groove (54) because of elastic deformation of the brake support (10). 
     
     
       4. The spot-type disc brake as claimed in claim 2, characterized in that the groove (54) of at least one guide (30) which is relived of braking forces during braking in the normal direction of rotation (22) of the brake disc (12) is deepened by a slot (64) of limited axial length, and that the associated projection (56) carries a pin (66) which engages in the slot (64) and limits the axial movability of the sliding caliper (28) without participating in the transmission of braking forces. 
     
     
       5. The spot-type disc brake as claimed in claim 1, characterized in that with each guide (30, 32) an elastic cup (70) is associated which is sealingly secured with one of its ends (68) to the associated guide body (50) and is guided on a cylindrical shank (58) carrying the associated projection (56) with a sealing lip (72) formed at its other end and that the sealing lip (72) is stiffened at its end facing the associated groove (54) by a metal ring (74) fixedly connected thereto, the lip (72) being protected by the ring (74) from becoming jammed in the groove (54). 
     
     
       6. The spot-type disc brake as claimed in claim 1, wherein the guide body (50) is divided into a support body (78) and a slide body (80) of harder material than said support body (78) and in which the groove (54) is formed. 
     
     
       7. The spot-type disc brake as claimed in claim 6, wherein the support body (78) has a V-shaped groove (82) therein, the slide body (80) on the side thereof opposite the projection-receiving groove (54) being embedded in the V-shaped groove (82) of the support body (78).